a) Field of the Invention
The invention relates to a device for the treatment of obesity comprising a band annularly placeable about the stomach with closure means for closing the band to form a ring and an enveloping part connected or connectable with the band for enveloping a gastric region adjoining the applied band.
b) Description of Related Prior Art
Devices for treating obesity by means of a band annularly placeable about the stomach, which band is closable by closure means to form a ring, are known in various implementations and are most frequently referred to as gastric bands. Such a gastric band is disclosed, for example in EP 0 702 529 B1. The band, which can be placed annularly about the stomach, includes a longitudinally extending inner hollow chamber and at the two ends of the band first and second closure parts are disposed, which can be latched in position with one another to close the band. To constrict the passage cross section of the gastric band opening of the closed gastric band, the hollow chamber is filled with the desired quantity of filler medium. This filling takes place through an injection port connected with the gastric band via a tubule, which port is subcutaneously implanted in the patient. Further gastric bands with adjustable passage cross section are disclosed, for example, in US 2004/0158272 A1, US 2004/0260319 A1 and US 2004/0267377 A1.
Gastric bands are conventionally wrapped about the stomach in the proximity of the inlet of the esophagus. If a gastric band is placed further down, the gastric reservoir remaining above the band is relatively large and the stomach, moreover, can become dilated in this region such that the desired weight loss is not attained. If the stomach is constricted, as is customary, far above in the proximity of the inlet of the esophagus, the food taken in by the patient can only slowly pass through this constricted region. It is therefore possible for the ingested nourishment to accumulate in the region of the distal esophagus. Contrary to its natural function, the distal esophagus is consequently utilized as a reservoir for food. A possible long-term complication is the development of a dilatation of the distal esophagus, upon the occurrence of which the gastric band must be removed.
A gastric band of the above described type is disclosed in EP 1 669 045 A1. To prevent expansion of a gastric region proximal to the gastric band, an enveloping part is fastened on the band, which part projects laterally in the proximal direction. After implantation of the band, the enveloping part encompasses a gastric region proximal to the gastric band in the manner of a collar and elastically supports the gastric wall enveloped by it.